Stop Start Technology

[johnnybegood]

I have wondered about this can somebody explains how it works (Techinically).

And what is the effect on the engine as motorists are lead to believe that when you start a car you use a petrol and also a lot of engine wear occurs when a car is started so is this technology really benificial?

[QuackHandle]

I was under the impression that most systems are designed so the engine is on some sort of standby mode, like you would have with a television, so it's not the same as if you were to remove the key and start the engine again.

[HellDiver]

johnnybegood said:

I have wondered about this can somebody explains how it works (Techinically).

If the car is in neutral, handbrake on, no pedals pushed, and the battery is fully charged and the heater or aircon don't need the engine, then the engine shuts off. As soon as you press the clutch to engage a gear, the engine starts up.

[StottyZr]

HellDiver said:

johnnybegood said:

I have wondered about this can somebody explains how it works (Techinically).

If the car is in neutral, handbrake on, no pedals pushed, and the battery is fully charged and the heater or aircon don't need the engine, then the engine shuts off. As soon as you press the clutch to engage a gear, the engine starts up.

furthermore it will only do this once the car is up to temperature.

[RizzoTheRat]

Startup engine wear issues are presumbaly more of an issue on a cold engine, when the engine's nice and warm and everything's already coated in warm oil I guess it's less of a problem.

[mrmr96]

RizzoTheRat said:

Startup engine wear issues are presumbaly more of an issue on a cold engine, when the engine's nice and warm and everything's already coated in warm oil I guess it's less of a problem.

I believe the cars will only do 'start/start' when a number of conditions are met, which includes the following (probably)
- Sufficient charge in the battery
- Engine up to temperature
- Sufficient fuel(?)
- Sufficient lenght of time since last shutoff.

They also have beefier batteries, alternators and starter motors to cope with the additional strain of starting and stopping. I'd like to think they would also run a modified oil pump system, so as to keep oil flowing prior to each restart.

[shoestring7]

HellDiver said:

johnnybegood said:

I have wondered about this can somebody explains how it works (Techinically).

If the car is in neutral, handbrake on, no pedals pushed, and the battery is fully charged and the heater or aircon don't need the engine, then the engine shuts off. As soon as you press the clutch to engage a gear, the engine starts up.

IIRC the engine stops just before TDC so that it is in the optimum position for a restart.

SS7

[Chicane-UK]

My Fiat 500 has this and it seems pretty good.... as has been said, there are various caveats about when the system will and will not activate if, for example:

• The car is not part way up to temperature
• If there is high accessory load (wipers, lights, heater, etc)
• The battery is significantly discharged

It's kind of cool to knock the car out of gear and coast up to a junction, and feel the engine cut out. But everything continues working, including power steering as that's electric! Then as soon as your foot goes on the clutch, the car starts up..

[durbster]

I wonder if using the stop/start system is more fuel efficient at traffic lights than judging your timing right so you don't have to stop at all...

[Justayellowbadge]

I've always considered stop and start technology to be a minimum requirement in a car.

[jesta1865]

Justayellowbadge said:

I've always considered stop and start technology to be a minimum requirement in a car.

subtle very subtle.

i have always wondered about the wear on a turbo on one of these engines, i was always told to wait 10 - 15 seconds at idle when i stop in a turbo car to let it slow right down before it loses oil pressure.

is the oil now kept up to pressure by an electric pump or has turbo technology moved on loads?

[RizzoTheRat]

Hardly new though, a mate had this on a Polo on about a B plate

[shortar53]

Friend of mine has a Smart ForTwo MHD, and it will cut the engine under braking when speed is below 5mph - quite an odd sensation.

[anonymous-user]

I never understood why people like this.
It isn't much hassle to use the strange, key shaped device that turns.

[lyonspride]

It's nothing but a sales gimmick, the actual savings are minuscule. In fact long term you'll probably end up forking out more in repairs/parts.

Last week I saw someone in a Clio who was clearly trying to manually stop/start whilst sat in traffic , seemed to work ok at first, but being directly behind I could tell the battery was not liking this, several stops later the battery promptly died.... And the driver? Yes she actually looked surprised!

[RESSE]

Back in 1986 in I had a VW Polo Formel E (1300cc/B registration), and it had a switch on the dashboard, and when said switch was engaged the engine would cut out if you were:

1. Stationary for more than x seconds.
2. In Neutral.

Novelty back then, or can anyone give details of other cars with this OEM supplied bit of kit?

[cptsideways]

If you read some manfacturer figures the average annual savings are minimal, like 5-10l of fuel per year. The only real benefit is in road tax savings due to the EU drive cycle emmissions which we all know are pony anyway.

Some of the tech is quite clever, like the Mazda system that fires one cylinder to restart, its does'nt use the starter motor. They all require a certain driving adjustment to make it work, like bieng in nuetral & off the pedals, which many drivers don't do anyway. The BMW systems often can't make their mind up, the logic system is all wrong on them!

I would'nt be buying a car based on it, though the road tax savings yes.

[rumbletum]

My wife's Ka has it. It seems to work really well.

It even manages to 'know' when you are parking/manouvering and doesn't cut out when it would be annoying for it to do so.

And you can disable it at any time if you want just by pushing a button on the centre console.

[HellDiver]

PSBuckshot said:

I never understood why people like this.
It isn't much hassle to use the strange, key shaped device that turns.

Because turning off the key makes the radio, the heater fan, the lights, etc, etc all stop working.

[RobCrezz]

Justayellowbadge said:

I've always considered stop and start technology to be a minimum requirement in a car.